Destroy the invading aliens and save your brethren from abduction.
Cursor keys - move
A or Spacebar - Fire (hold down for rapid fire)
S - Smart bomb (destroys everything on the screen)
D - Hyperspace (teleports you to a random area)
If an alien abducts one of your friends from the bottom of the screen, you can shoot the alien and your friend will drop. Try and catch your friend and land them safely on the ground.
Every 5000 points earns you another smart bomb, every 7500 points earns you another life.